A method of making a polymer composite from a mixture of a polymeric material, carbon nanofibers, and nano-scale particles is provided. The carbon nanofibers are less than about 1 micrometer in diameter, and the nano-scale particles are shorter in length than the carbon nanofibers. The nano-scale particles are selected from nano-scale carbon additives, non-conductive nano-clays, nano-scale conductive metallic additives, or combinations thereof. The components are mixed to form a polymer composite. A polymer composite having a resistivity of less than about 107 ohm-cm is also described.